49ERS’ SMITH HAD STRONG FIRST HALF, PRIMED FOR BIG FINISH

When Alex Smith is good he can be very good. When Smith is very good, the San Francisco 49ers are practically unbeatable.

While the staples of San Francisco’s success this season remain a rock-solid defense and the NFL’s top-ranked rushing game, Smith’s play at quarterback has been a key variable that’s put the 49ers over the top in a string of lopsided victories.

The first-place 49ers begin the second half of the season Sunday against the St. Louis Rams at 6-2 with a 1½-game lead in the NFC West. The six victories have come by an average margin of 20 points, and the former Helix High star has a 120.0 quarterback rating in those games.

He is coming off one of the best performances of his career as the 49ers return from their bye week, but Smith knows his strong season to this point will ultimately be judged by what he and the 49ers do the rest of the year.

“You hope you’re playing your best football come November and December,” Smith said. “As you move into the back half of the season, these are huge games, so you hope you’re playing better and better as the season goes on.”

Around the league

Bears star cornerback Charles Tillman said on Twitter that he will play Sunday against the Texans, after all. Tillman’s status had been up in the air after he told Chicago radio station WSCR-AM that he might not be available because his wife, Jackie, is due to give birth.

• Safety Antrel Rolle warned the Bengals’ A.J. Green to “duck” in Sunday’s game after the receiver said in a radio interview that there were “a lot of holes” in the Giants’ defense,
ESPNNewYork.com reported.

• Raiders defensive lineman Richard Seymour missed his second straight practice with a lingering hamstring injury and is questionable to play at Baltimore.

• For the second straight year, Lions defensive tackle Ndamukong Suh has been voted the NFL’s dirtiest player in a poll of players by the Sporting News. Suh received 32 votes in the poll that included 103 players.

• Wide receiver Calvin Johnson said he suffered nerve damage from hits suffered in the Lions’ loss to the Vikings in September, which made it hard for him to grip the ball, the Detroit Free Press reported.